There is increasing interest in the exposure science field in top-down approaches to studying human environmental exposures (the exposome), where toxicants of interest are profiled within the body through blood and/or other biological samples. Such studies would complement more traditional bottom-up approaches where the environment in which an individual lives is sampled and studied to identify potential causes of disease. The long-term goal of the work proposed in this application is to create highly multiplex sensors to facilitate not only the detection of environmental toxicants in serum samples, but to also profile the immune or other biological response induced by these potential exposures. Through previous work funded by the NIEHS, Adarza BioSystems has developed a portable, multiplex protein detection system designed to profile biological response to toxic exposures from a finger-stick volume of blood. By measuring the levels of cytokines and other protein biomarkers, health status information related to inflammation, oxidative stress, and coagulation can be quickly assessed in the field using this tool, without the need for centralized laboratory facilities. In this application we seek to apply this core detection technology for the first time,to the direct detection of environmental toxicants linked to human disease. Specifically, a 5-plex array will be developed in Phase I that will target Bisphenol A, Triclosan, Benzo[a]pyrene, Napthalene, and Chlordane. Aim 1 will develop the required functional array probes that will be used to optimize the assay protocol in Aim 2. The detection sensitivity for all target compounds will then be measured in Aim 3. In a future Phase II effort, this demonstration array will be expanded with additional toxicant content and added to Adarza's existing environmental response biomarkers, creating a single detection platform that will simultaneously profile known toxicants and their biological response from a single drop of blood.